MRI
Large nidus of malformed vessels with serpiginous appearance (bag of worm) involving almost whole left frontal lobe. The nidus measures 6.3x6.3x4.9cm (APxWxCC).
Arterial supplies to AVM are from the following arteries: left anterior cerebral artery (fronto-polar), left middle cerebral artery (M2 insular segment), frontal branches of left superficial temporal artery from left external carotid artery.
Multiple superficial and deep draining veins:
-Superficially: adjacent frontal cortical veins draining into superior sagittal sinus.
-Deep: Another large tortuous draining vein coursing the left suprasellar cistern, left ambient cistern (enlarged left basal vein of Rosenthal) and quadrigeminal plate to join vein of Galen and to straight sinus. Both internal cerebral veins are not dilated.
Both internal carotid arteries are larger in calibre. No aneurysmal dilatation noted at circle of Willis or within the nidus of AVM.
No gliosis seen in brain parenchyma.
No abnormal appearance of blooming artefacts to suggest recent or previous haemorrhage.
Significant midline shift to the right side by 0.7cm (measured to septum pellucidum at foramen of Monro). Left lateral ventricle is partially effaced by the AVM.
No obvious thrombus within the cerebral venous sinuses.
No restricted diffusion in DWI/ADC to suggest acute infarction.
Mucosal retention cyst within the left maxillary sinus.